A new genus, Zhurbenkoa, and a novel nutritional mode revealed in the family Malmideaceae (Lecanoromycetes, Ascomycota)

ABSTRACT

Lichen-inhabiting fungi are highly specialized mycoparasites, commensals or rarely saprotrophs, that are common components of almost every ecosystem, where they develop obligate associations with lichens. Their relevance, however, contrasts with the relatively small number of these fungi described so far. Recent estimates and ongoing studies indicate that a significant fraction of their diversity remains undiscovered and may be expected in tropical regions, in particular in hyperdiverse fog-exposed montane forests. Here, we introduce the new genus Zhurbenkoa, from South America and Europe, for three lichenicolous fungi growing on thalli of the widespread lichen genus Cladonia (Lecanorales). Phylogenetic analyses based on combined sequence data of mt and nuc rDNA obtained from Andean populations (Bolivia) placed Zhurbenkoa as a member of Malmideaceae, a recently introduced family of lichen-forming fungi in the class Lecanoromycetes. Zhurbenkoa is closely related to the genera Savoronala and Sprucidea. The new genus is characterized by the development of grayish brown to almost black apothecia lacking an evident margin, an epihymenium interspersed with crystals (often seen as pruina), a strongly conglutinated hymenium made of noncapitate and sparsely branched paraphyses, a colorless exciple composed of radially arranged hyphae, a Lecanora/Micarea-like ascus type, and aseptate or 1-septate ellipsoidal colorless ascospores. Zhurbenkoa includes two Neotropical (Z. cladoniarum, Z. latispora) and one widespread (Z. epicladonia) species. The lichenicolous trophic mode is documented for the first time in the Malmideaceae, which until now included only lichen-forming associations between fungi and green algae.

KEY WORDS:

• Arthonia epicladonia
• lichenicolous fungi
• Neotropics
• Pezizomycotina
• phylogenetics
• systematics
• 4 new taxa

ACKNOWLEDGMENTS

We are greatly indebted to our colleagues and all staff of the Herbario Nacional de Bolivia, Instituto de Ecología, Universidad Mayor de San Andrés, La Paz, for their generous long-term cooperation. We would also like to thank the SERNAP (http://sernap.gob.bo), and all protected areas staff, for providing permits for scientific studies, as well as their assistance and logistical support during the field works. We thank especially Paul Diederich (Luxembourg) and an anonymous reviewer for their valuable comments on the manuscript, and also the curators of the cited herbaria for a loan of the specimens used in the study.

Additional information

Funding

This research was financially supported by the National Science Centre (NCN) in Poland (DEC-2013/11/D/NZ8/03274). A.F. and P.R.F. received additional support under statutory funds from the W. Szafer Institute of Botany, Polish Academy of Sciences, Krakow, Poland. S.P.O. was supported by the grant RYC-2014-16784 from the Spanish Ministry of Economy, Industry, and Competitiveness. Z.P. acknowledges the support by the Academy of Science of the Czech Republic (AV0Z60050516, RVO 67985939).